Marine engine cooling

ABSTRACT

Improved water jacketed manifolds for marine engine cooling systems of the type wherein heated water which has circulated through an engine cooling system for cooling purpose is mixed in the improved engine exhaust manifold water jacket according to this invention with raw, relatively cool water to controllably cool the manifold and avoid condensing water from the exhaust gases flowing through the exhaust manifold.

United States Patent [191 Pace [451 Dec. 25, 1973 1 MARINE ENGINECOOLING [75] Inventor: John G. Pace, Port Huron, Mich.

[73] Assignee: Chrysler Corporation, Highland Park, Mich.

221 Filed: Nov. 13, 1972 21 App1.No.: 306,247

Related U.S. Application Data [62] Division of Ser. No. 127,489, March24, 1971, Pat.

[52] U.S. Cl l23/4l.08, 123/4131, 60/321, 2 165/51, 165/100 [51] Int.Cl. F28f 27/02, FOln 3/04, Flp 3/12 2,284,381 5/1942 DuPont 123/4108 X2,327,342 8/1943 Drapeau 123/41.09 2,478,489 8/1949 Kelson, Sr 123/41082,757,650 8/1956 Holley 60/320 X 3,283,498 11/1966 Connell 60/321 X3,358,654 12/1967 Shanahan ct a1. 60/321 X 3,319,614 5/1967 Shanahan123/4108 3,380,466 4/1968 Sarra 123/4109 X 3,485,040 12/1969Niskanen.... 60/321 X 3,696,620 /1972 Pace /321 Primary Examiner-AlLawrence Smith Attorney-Oliver F. Arrett ABSTRACT Improved waterjacketed manifolds for marine engine cooling systems of the type whereinheated water which has circulated through an engine cooling system forcooling purpose is mixed in the improved engine exhaust manifold waterjacket according to this invention with raw, relatively cool water tocontrollably cool the manifold and avoid condensing water from theexhaust gases flowing through the exhaust manifold.

3 l im. .2zawi fi ere MARINE ENGINE COOLING This is a division ofapplication Ser. No. 127,489 filed Mar. 24, 1971 now U. S. Pat. No.3,734,170.

BACKGROUND OF THE INVENTION This invention relates to improved raw watercooling systems for marine engines and particularly to improvedwaterjacketed exhaust manifolds therefor. The term "raw water as usedherein is meant to refer to water which has been freshly pumped into butnot circulated through the engine cooling system and has therefore notabsorbed any heat from the various engine components. Heretofore, rawwater was pumped through engine cooling systems wherein watercirculation was controlled by a thermostatic valve. The valve dumpedsome water from the system when the water reached a predeterminedtemperature and allowed raw, relatively cool water to be added to thesystem to replace the dumped water and lower the temperature of thewater flowing through the system. Various arrangements have been used tocool the engine manifolds, such as circulating raw water therethroughand even pre-mixing raw water with some of the heated water from thecooling system.

Such systems have tended under certain weather conditions, such as thoseprevalent in early Spring and late Fall when raw water is particularlycool, to overcool the manifolds and cause condensation of water from theexhaust gases to occur in the manifolds. The condensate tended to drainback into the engine with undesirable effects. To meet this problem theprior art has for example, used separate mixing chambers wherein heatedcirculating water and raw water have been mixed together prior tocirculation through the manifold water jackets. However, sucharrangements have been overly complicated from the standpoint of theexterior hose arrangement required on the engines. It is an object ofthis invention to prevent such condensation by providing a coolingsystem with anticondensation features in the engine manifold waterjackets wherein mixing or tempering of the raw water occurs in thejacket by means of special structure. This, in addition to otheradvantages, makes less complicated exterior plumbing or hosearrangements possible on the engine.

It is a general object of this invention to circulate both raw water andheated water from the engine cooling system through marine engineexhaust manifold jackets, allowing the raw and heated water to mix tovarying degrees in the jacket, depending on the demands of the system,thus limiting the temperature to which the manifold is cooled. It mayalso be said that it is an object of this invention to provide acontrolled temperature for marine engine exhaust manifolds which avoidsexhaust condensation and also allows the manifold water jacekt to serveas a point at which the cooling system replenishes dumped water with rawwater.

SUMMARY OF THE INVENTION This invention comprises marine engine waterjacketed exhaust manifolds having ordinary water inlet and outletarrangements for circulating the engine cooling .water through the waterjacket. The invention also comprises cooling systems utilizing thesemanifolds. A jacketed manifold according to this invention will includea raw water inlet and outlet adapted for allowing the flow of raw waterthrough the jacket and wherein the raw water outlet will be mutuallyarranged relative to each other to provide a preferred flow or path forthe raw water through the jacket with minimal mixing between it and thecirculating heated water in the jacket which comes from the enginecooling system. Minimal mixing is maintained except for times when thecirculating water requires additional raw water to replace water whichhas been dumped from the cooling system. In a preferred embodiment thisis accomplished by structure comprising a tube which is positionedlongitudinally in the manifold water jacket. The tube includes an inletend spaced a short distance from the raw water inlet on the manifoldjacket to provide a gap therebetween which functions as a means forintroducing raw water into the circulating water of the cooling systemproper. The tube also includes an outlet end which is connected to theoutlet on the manifold water jacket.

When heated water, which has flowed through the engine cooling system,is introduced into the manifold water jacket, water tends to fill thejacket to the level at which the tube is positioned therein. This watertends to flow out of the usual manifold jacket outlet at the other endthereof and is then circulated through the engine cooling system. Rawwater entering the raw water inlet of the manifold jacket tends to flowacross the gap into the tube inlet and out the raw water outlet so longas the manifold jacket proper is substantially full of water from theengine cooling system. When, however, water from the cooling system hasbeen dumped due to an increase in the temperature thereof, the volume ofthe water in the manifold jacket proper decreases correspondingly. Someof the raw cool water flowing across the gap into the inlet tube thentends to fall down into the manifold jacket proper and mix with thewater from the engine cooling system. The water which has been dumped isthus replaced by the mixing action in the manifold jacket. This mixingaction occurs until the engine cooling system pump has been satisfied asto the volume of water required to fill the cooling system and providethe proper cooling function at which time the exhaust manifold waterjacket is again substantially full of water from the engine coolingsystem and most of the raw water flowing through the raw water inletagain bridges the gap and preferentially flows through the tube and outof the raw water outlet to be dumped or otherwise disposed of ratherthan mixing in the jacket. Structural arrangements other than the tubeand gap may be usedto accomplish these ends as will be indicatedhereinbelow.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic top elevation,with certain parts disassembled or exploded, of a V-8 marine enginehaving a raw water cooling system according to the present invention.

FIG. 2 is a front elevation of the engine shown in FIG. 1.

FIG. 3 is a schematic diagram of a preferred raw water cooling systemaccording to the present invention.

FIG. 4 is a cross-section through line 3-3 of FIG. 2 showing typicalmanifold structure for marine engines.

FIGS. 5 and 6 are cross-sectional representations of another embodimentof the invention.

FIG. Tis a cross-sectional representation of yet another embodiment ofthe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A marine engine generallydesignated at is shown in FIGS. 1 and 2. The engine is equipped with araw water cooling system according to the present invention. The coolingsystem includes a water pump means 12, a thermostatic valve 16, waterjacketed exhaust manifolds 18a and 18b, terminating in exhaust elbows20a and 20b, and appropriate conduit means such as interior passages inthe engine block per se and exterior lines, such as rubber hoses, forinterconnecting these elements to provide water circulationtherebetween.

Pump means 12 may be a dual pocket pump. This type of pump is capable ofproviding two flow outputs in different paths simultaneously. As can be.seen in FIGS. 1 and 2, pump 12 provides flow outputs of water taken inat an inlet line 22 which leads to the internal portion of the enginecooling system at 24 and into lines 26a and 26b which lead to inlets 28aand of the water jackets for manifolds l8. I

Line 22 serves as the beginning for the engine cooling system proper. Aspreviously indicated it conducts water from pump 12 to the interiorcirculating system of engine 10. Water flows from engine 10 tothermostatic valve 16" through line 23 (shown in FIG. 2). Whenthermostatic valve 16 is closed, that is when the circulating water isbelow a predetermined temperature, water will flow from it to inlets 30aand 30b through lines 320 and 32b, respectively to enter the waterjackets of the manifolds.

Due to internal structure in the manifold jacket, which will bedescribed in detail hereinbelow, water entering inlets 30a and 30b willfor the most part leave the jackets throughoutlets 34a and 34b (shown inFIG. 1) respectively whereas water entering inlets 28a and 28b willforthe most part leave the jackets by flowing directly therefrom into theexhaust elbows where it will mix withthe exhaust gases. Water may beconducted from outlets 34a and 34b to an oil cooler 36 by. lines 38a and38b and Tee 40 (shown in FIG. 1). From the oil cooler, water flows backto the front pocket of pump 12 by means of line 42 (shown in FIG. 1).

When thermostatic valve 16 opens, that is when the temperature of thecirculating water substantially reaches the predetermined temperature,some of the circulating water in the cooling system is dumped via line44 and lines 460 and 46b into exhaust elbows 20a and 20b where the watermixes with the exhaust gases and is discharged therewith through theengine exhaust system.

Referring now to FIG. 3, a raw water cooling system according to thepresent invention is shown in a somewhat diagrammatic fashion forclarity and convenience in order to describe the improved water jacketstructure according to this invention and the Operation of the overallsystem. As in all the Figures, similar elements are identified by thesame numbers throughout the drawings. The arrows in the Figure indicateflow paths through the various elements of the system. The system iscomprised of cooling lines interconnecting pump 12 and engine 10 vialine 22, engine 10 and thermostatic valve 16', via line 23, thermostaticvalve 16 and exhaust manifold water jacket 18 at inlet 30 via line 32,and water jacket 18 at outlet 34 to pump means 12 via line 38, oilcooler 36 and line 42. Water circulates through this part of the systemcooling the engine and the exhaust manifold. When the water exceeds acertain predetermined temperature, such as l40 to F. For example,thermostatic valve 16 dumps some water overboard by means of lines 44and 46 which lead to exhaust elbow 20, as previously. noted. Althoughcertain of the elements described may actually be present in pairs, suchas the manifolds 18a and 18b and the like, only one of each has beenshown in FIG. 3 for simplicity and identified by the number only, suchas manifold 18. j 1 w Raw water flows through line 26 which extends frompump means 12 to the exhaust manifold jacket 18 by means of which coolraw water may flow to the jacket inlet 28. An outlet 48 (shown in FIG.3) at the opposite end of the exhaust manifold jacket, communicates withexhaust elbow 20 for dumping water entering at inlet In operation, whenthermostatic valve 16 is closed and water is flowing through the enginecooling system, water will flow through the exhaust manifold jacket byentering inlet 30 and substantially fill the manifold jacket, asindicated in the drawing wherein the water level is almost to the top ofthe jacket. The water will then flow out of outlet 34 at the other endof the exhaust manifold jacket to continue circulatory flow to the pumpand again be circulated through the engine 10 and so on. Whenthermostatic valve 16 opens due to increased water temperature and dumpssome of the heated water from the system through lines 44 and 46, thedumped water must be replaced by an additional amount of cool raw water.This is provided by means of the preferred arrangement which is shown inthe exhaust manifold jacket 18 of FIG. 3. As can best be seen in thatFigure and in FIG. 4, the exhaust manifold water jacket 18 includes atube, such as brass tube 50, which is positioned in the upper portion ofthe jacket with an inlet end 52 maintained at a predetermined distancefrom raw water inlet 28 on water jacket 18. There is thus provided a gapbetween inlet 28 and the inlet end 52 of tube 50 which water musttraverse in order to enter the tube. The outlet end 54 of tube 50 isconnected to jacket raw water outlet 48 as shown at the opposite'end ofthe exhaust manifold jacket.

Thus, when thermostatic valve 16 is closed and the cooling system hassubstantially filled exhaust manifold jacket 18 with circulating water,raw cooling water flowing through line 26 will tend to traverse the gapwith minimal mixing with the circulating water in the jacket, enter tube50 and flow out the outlet end to be dumped overboard through exhaustelbow 20 and the engine exhaust system. However, when thermostatic valve16 opens to dump water through lines 44 and 46, the volume of water andthe water level in the exhaust manifold jacket will fall to a lowerlevel and some of the raw water entering the jacket through line 26,which has heretofore traversed the gap and entered tube 50, will fallinto the lower main body portion of the exhaust manifold jacket to mixwith the water contained therein. It will then flow through outlet 34 tocirculate through the engine cooling system proper. The mixing action ofthe raw cool water and the heated circulating water thus providedcontrols the temperature of the exhaust manifolds to prevent exhaust gascondensation therein and also provides additional cooling-water for theengine cooling system to replace that which has been dumped overboard bythermostatic valve 16. The pumping demands placed upon the water inexhaust manifold jacket 18 by pump 13 will inherently provide mixing ofraw cool water with previously circulated water in the manifold jacketto control the exhaust manifold to a desired temperature range and toregulate the mixing requiremenet of the water in the cooling system.Mixing will also be in part controlled by the degree of the thermostatopening when water is being dumped.

Exhaust manifold water jacket 18 has been shown somewhatdiagrammatically but it is to be understood that the preferred structureis of the standard type, which is well known in the art. F IG. 4 showssuch a type having a central conduit or manifold 56 for exhaust gasessurrounded by jacket 18 through which the water may flow for cooling themanifold and the gases. In the upper portion, tube 50 is preferablypositioned as shown.

It can be seen that according to this invention and particularly in thepreferred arrangement wherein tube 50 has an inlet 52 in the proximityof raw water inlet 28, a path is provided, through the tube in thepreferred embodiment, which the raw water prefers when the jacket issubstantially full of circulating water. When water is dumped from thecooling system, the preferred path is disturbed and the raw water tendsto mix in relatively large amounts with the circulating water in thejacket until the balance of the system restores itself.

Only a preferred structure has been described in detail but others arepossible wherein a raw water inlet and outlet are arranged close to eachother in an upper portion of a water jacketed manifold to provide a moreor less normal and preferred path therethrough for raw water when thejacket contains its normal complement of circulating water and whereinthe raw water path is disturbed to cause mixing of the raw water withthe circulating water when that normal complement has diminished, as bydumping.

For example, Figures 5 and 6 show one from which a manifold may takewherein a structure provides the preferred path without the necessity ofa tube. In this embodiment, raw water inlet 28 and raw water outlet 48are oppositely disposed each other but in a relatively close spatialrelationship to provide a gap, similar to that between inlet 28 and tubeinlet 52 shown in FIG. 3, without a tube per se. They are located in araised upper portion 58 of manifold jacket 18. The other inlet andoutlet pair 30 and 34 are located as before in opposite end portions ofthe jacket. Exhaust conduit 56 is centrally located therein as is usual.When the jacket is substantially full of circulating water, that is to alevel just below inlet 28 and outlet 48, raw water will flow betweeninlet 28 and outlet 48 with very little mixing.

However, when the water level drops in the jacket proper, as bythermostatic dumping, water entering inlet 28 will fall into the jacketproper until the level thereof is restored as previously described.

Similarly, another embodiment is shown in FIG. 7 which comprises anordinary water jacketed manifold 18 with the closely spaced raw waterinlet 28 and outlet 48 provided as required by this invention. Theoperation thereof requires no further explanation in view of thatalready presented in connection with the other Figures. 8

The preferred embodiment wherein a tube is used for the flow of rawwater through the length of the manifold jacket has the added advantage,when the tube is a good heat exchange material, such as copper, brass orstainless steel, of establishing a desirable heat exhange relationshipbetween the raw water flowing therethrough the circulating water in thejacket proper.

Having described the invention an exclusive property right is claimedaccording to the following:

1. A water jacketed marine engine manifold comprisa central conduit forcarrying exhaust gases from the engine;

a water jacket surrounding the central conduit;

a water inlet and outlet pair in the jacket adapted to be connected toan engine cooling system for circulating water through the jacket;

another water inlet and outlet pair in the jacket for providing a flowof raw water therethrough, the inlet and outlet being closely disposedrelative to each other and in a higher position in the jacket then thefirst mentioned pair.

2. The manifold according to claim 1 wherein:

the raw water inlet is substantially at one end of the jacket and theraw water outlet is provided by the open end of a horizontally disposedtube in the jacket;

the open end thereof being disposed relatively close to the raw waterinlet, the opposite end of the tube being connected to an outlet openingat the substantially opposite end of the jacket whereby alternate pathsfor water entering the raw water inlet are established, the first pathbeing through the tube, the second path being through the jacket proper.

3. The manifold according to claim 2 wherein:

the tube is made of a heat exchange material to promote heat exchangebetween the cool water flowing therethrough and the heated water in thejacket.

1. A water jacketed marine engine manifold comprising: a central conduitfor carrying exhaust gases from the engine; a water jacket surroundingthe central conduit; a water inlet and outlet pair in the jacket adaptedto be connected to an engine cooling system for circulating waterthrough the jacket; another water inlet and outlet pair in the jacketfor providing a flow of raw water therethrough, the inlet and outletbeing closely disposed relative to each other and in a higher positionin the jacket then the first mentioned pair.
 2. The manifold accordingto claim 1 wherein: the raw water inlet is substantially at one end ofthe jacket and the raw water outlet is provided by the open end of ahorizontally disposed tube in the jacket; the open end thereof beingdisposed relatively close to the raw water inlet, the opposite end ofthe tube being connected to an outlet opening at the substantiallyopposite end of the jacket whereby alternate paths for water enteringthe raw water inlet are established, the first path being through thetube, the second path being through the jacket proper.
 3. The manifoldaccording to claim 2 wHerein: the tube is made of a heat exchangematerial to promote heat exchange between the cool water flowingtherethrough and the heated water in the jacket.